Re: HTTP 1.1 issue 20: 13.1.2 Warnings
Jim Gettys (jg@pa.dec.com)
Wed, 11 Nov 1998 09:51:01 -0800
Has anyone ever told you that you'd have a great future as a copy editor?
:-).
> -----
> In section 13.1.2 "Warnings", the statement
>
> "The first digit indicates whether the Warning MUST or MUST NOT be
> deleted from a cached response after it is successfully
> revalidated.
>
> does not specify a requirement. The "MUST or MUST NOT" should be
> changed to "must or must not".
>
This, plus your issue 18 point out duplication in section 14.46
text with section 13.1.2...
In section 13.1.2 we find:
Warnings come in two categories:
1. Those that describe the freshness or revalidation status of the response,
and so MUST be deleted after a successful revalidation (see section 13.3
for a definition of revalidation).
2. Those that describe some aspect of the entity body or entity headers
that is not rectified by a revalidation, for example, a lossy compression
of the entity bodies. These warnings MUST NOT be deleted after a successful
revalidation.
Warnings are assigned 3-digit code numbers. The first digit indicates
whether the Warning MUST or MUST NOT be deleted from a cached response
after it is successfully revalidated. This specification defines the code
numbers and meanings of each currently assigned warning, allowing a client
or cache to take automated action in some (but not all) cases.
In section 14.46 we find:
The warn-code consists of three digits. The first digit indicates whether
the Warning MUST or MUST NOT be deleted from a stored cache entry after
a successful revalidation:
1xx Warnings that describe the freshness or revalidation status of the
response, and so MUST be deleted after a successful revalidation. 1XX
warn-codes MAY be generated by a cache only when validating a cached entry.
It MUST NOT be generated by clients.
2xx Warnings that describe some aspect of the entity body or entity
headers that is not rectified by a revalidation, and which MUST NOT
be deleted after a successful revalidation.
These are close to identical, in slightly different ordering, but with
a few differences (e.g. the lossy compression reference, and the additional
requirements on 1xx codes in 14.45).
I propose we clean this up (and shorten the specification) by replacing
the 13.1.2 text noted above with:
Warnings are assigned three digit warn-codes. The first digit indicates
whether the Warning MUST or MUST NOT be deleted from a stored cache
entry after a successful revalidation:
1xx Warnings that describe the freshness or revalidation status of the
response, and so MUST be deleted after a successful revalidation. 1XX
warn-codes MAY be generated by a cache only when validating a cached entry.
It MUST NOT be generated by clients.
2xx Warnings that describe some aspect of the entity body or entity headers
that is not rectified by a revalidation (for example, a lossy compression
of the entity bodies) and which MUST NOT be deleted
after a successful revalidation.
See section 14.46 for the definitions of the codes themselves.
And replace the 14.46 text with:
The caching behavior of warnings is discussed in section 13.1.2.
This should reduce duplication and resulting confusion (and shorten the
document further).
- Jim